how to configure facility wide configuration files
You can do such a multi-leveled setup using scripting and automatically run script on each startup. Just in scripting panel you can create a new text block, name it with 'auto-config.py' (the extension have to be py), and in that script check whether or not proper blend files, addons, and custom presets are accessible.

In order to run the script with each Blender start, you have to mark 'register' checkbox in Text Editor. Then, save your blender startup file with this script. Next time, when Blender will be run, it will automatically run the script too, and what this script will do depends entirely on you. So, you can open any text files with custom configurations, import data from blend files and so on, using your multi-level path configuration or even cascading blender files setups. This will require some further coding.